## 14.5. Answer "Yes" or "No" Forever with yes

Some commands -- like rm -i, find -ok, and so on -- ask users to answer a "do it or not?" question from the keyboard. For example, you might have a file-deleting program or alias named del that asks before deleting each file:

>     % del *
>     Remove file1? y
>     Remove file2? y
>        ...

If you answer `y`, then the file will be deleted.

What if you want to run a command that will ask you 200 questions and you want to answer `y` to all of them, but you don't want to type all those `y` s from the keyboard? Pipe the output of `yes` to the command; it will answer `y` for you:

>     % yes | del *
>     Remove file1?
>     Remove file2?
>        ...

If you want to answer `n` to all the questions, you can do:

>     % yes n | del *

> NOTE: Not all Unix commands read their standard input for answers to prompts. If a command opens your terminal (/dev/tty (Section 36.15)) directly to read your answer, `yes` won't work. Try expect (Section 28.18) instead.

-- JP

Copyright © 2003 O'Reilly & Associates. All rights reserved.